Improvement in link-motions for operating valves



VILLARD KNOVVLES, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT iN LINK-MOTIONS FOR OPERATING VALVES.

Specilieation forming part of Letters Patent No. 4l 2,297, dated April12, 1864.

To all whom t may concern:

Be it known that 1,W1LLARD KNoWLEs, a resident of Boston, in the countyot' Suffolk and State ot' Massachusetts, have invented an Improved LinkMotion or Mechanism for the Valve of a Steam-Engine; and I do herebydeclare the same to be fully described in the following specificationand represented in the accompanying drawings, ot which- Figure l is atop view, and Fig. 2 a front elevation, of it.

My improvement is to be found in the peeuliar connection of the linkwith its operative lever-viz., by means of an are anda swing-block, orits equivalent.

The advantage of my improv( d. connection over the common rod connectionis that the former presents the wear ot' the sides of the link thatresults from the latter, the strain of which on the link tends to cantthe link on the pin of the valve-lever, and so as to wear the link onits opposite sides, the same rendering it necessary to plane down thelink in order to repair it. This reduction ot' the thickness of thelinkdiminishes its strength and durability, and, besides, isobjectionable in other respects. With my invention the link during itsmotions is always maintained in a vertical or one plane.

In the drawings, c represents the valvelever, which is connected Withthe open curved link b by means cfa pin, c, applied to the two in theusual manner. The two eccentric-rods d e are jointed to the said linkand applied to the eccentricsfg. The lever for raising and depressing`the link is shown at h, it being connected to the link by theswing-block t' and the circular are It. The said arc 7c is joined to theupper end of the link, and is clasped by the swing-block in manner asexhibited in Fig. 3, which is a vertical section of the two, and alsorepresents the pin l, by which the swing-block is connected With thelever h. This pin passes through the swingblock, and is xed in thelever, the said block being capable ot' turning or revolving on the pin.Each end ofthe link will receive motion from the eccentric-rod nextadjacent to it,what ever may be the extent of' elevation of the link orthe middle part of it. It is also evident that the valve-lever will bemoved the more by that eccentric-rod which may be the nearer to itsconnecting-pin. When the link may be depressed to a low position, thevalve-lever will acquire the motion ot' the upper eccentricrod, which isthat properrfor going ahead. When raised up into a high position, thevalverod will acquire the motion ofthe other eccentric-rod, or that forreversing the engine, while, when the connection pin of the valveleveris at the center of the link, such lever will have little or no motionimparted to it.

The link motion or mechanism obviates the necessity ot' throwing theeccentric-rod out of gear, and also enables the en gine to be worked toal certain extent expansively.

During the movements ot the link caused by the eccentric-rods the curvedare la will be moved longitudinally through the swing-block yi, whichwill swing or play on itspin l without causing any material movement ofthe lever lt. The are and the swing-block thus serve to preserve theconnection of the lever with the link, and allow of the necessarymovements ot' the latter. The longer arm ot' the lever h is representedin Fig. 2 by dotted lines, such arm being that which the engineer takeshold ot' in order to so move theV lever as to either raise or depressthe link.

.In the said link-motion, I claim-` The connection of the link with itsoperative lever, the same Ibeing by means of the curved are k and theswing-block t' or its equivalent.

NV ILLARD KNOW LES.

Witnesses:

R. H. EDDY, F. P. HALE, Jr.

